10-14-2013 05:12 PM
I am trying to figure out how to run a censored normal regression in SAS. I have cross-sectional data that I am analyzing to examine the association of an independent variable with systolic blood pressure (SBP). The observed SBP in treated individuals (HTNMed=1) is right censored, therefore I have been told to use censored normal regression. I have found how to do this in STATA (cnreg), but I can't seem to figure it out in SAS.
Does anyone know how to do this?
10-15-2013 08:29 AM
Do you have SAS/ETS licensed? If so, take a look at PROC QLIM.or PROC HPQLIM. I don't think there is a good way to approach this with SAS/STAT, but you might consider PROC LIFEREG for tobit regression--check Example 51.2 Computing Predicted Values for a Tobit Model, and see if you can substitute your values into the example there.
02-01-2014 06:11 PM
I have been successful in using Proc Lifereg to run censored normal regression for my analysis (thank you!). Now I am trying to predict mean outcome values (blood pressure) for 4 different models starting with a minimally adjusted model to one adjusting for all covariates, and am having trouble figuring out how to do this.
I tried to follow this example: http://support.sas.com/documentation/cdl/en/statug/63033/HTML/default/viewer.htm#statug_lifereg_sect..., but I'm starting to think that this is not the answer to my problem because my mean blood pressure is not changing more than a few tenths when I move from model 1 to model 4. I know this cannot be the case based on the results of the Proc Lifereg.
Does anyone know what I may be doing wrong or how to calculate mean outcome values for tobit models with right censoring?
Thank you in advance for any advice you have.